The subject matter disclosed herein relates generally to systems and methods for computed tomography (CT) imaging, and for coronary imaging using CT.
In CT imaging, an X-ray source may be rotated around an object to obtain imaging information. X-rays from the source attenuated by the object may be collected or detected by a detector and used to reconstruct an image. Motion of an object being imaged may present challenges to CT imaging. One example of an object to be imaged that may experience motion during CT imaging is a heart of a human patient. For example, cardiac motion may blur the coronary arteries in coronary CT angiography images, making it difficult for clinicians to perform an accurate diagnostic interpretation.
Reconstructing a cardiac volume at a phase of the cardiac cycle with the least motion may provide cardiologists with a more accurate representation of the coronaries; however, generating images at a multitude of cardiac phases and evaluating each of them to find the optimal phase creates a workflow problem for clinicians. Further, finding the best phase for different vessels may be difficult and time consuming for users if performed manually, resulting in relatively large expenditures of time and resulting in errors or inaccuracy. Conventional approaches may employ the use of default of standard or default phases or, alternatively, have a user manually select a phase. Manual selection may be time-consuming, while use of standard or default phases may be prone to error or unreliability, for example to patient variability.
To obtain a CT image of the heart, a practitioner may attempt to identify a particular phase (e.g., a most quiescent phase) of the heart and generate an image at that phase. However, selection of a most quiescent phase may be quite challenging, requiring expertise on the part of the practitioner and/or resulting in improper selection. For example, variability between patients and/or between different times of acquisition for the same patient may provide challenges to selecting a phase or performing other aspects of coronary CT imaging. Further, selection of a phase by a practitioner may be a time-consuming and/or labor intensive effort. Further still, manual selection may result in increased radiation dose and/or increased contrast agent dose.